How to Hard Reset the T-Mobile G1

1. If the device is turned on, turn it off.
   • Note: If the device is not responsive and does not turn off, remove the battery and re-insert it.
2. Press and hold the Home + Power key.
3. Keep holding for at least 25 seconds, even if  the 'Startup' screen appears.
4. Release the keys when you see a black screen with a warning sign.
5. Slide the keyboard open.
   • NOTE: As a shortcut, press ALT + W to factory reset the device. If this does not work continue with the below steps.
6. Press ALT+L.
7. Press ALT+W for 'wipe data/factory reset'.
8. You should then remove the battery and re-insert it. Then turn the device back on and allow it to startup.
   • NOTE: might take a few minutes longer than usual to bootup after performing this full reset